GpuParticleBuffer Class Reference

Manages a GPU storage buffer + CPU-side transfer buffer pair for particle data. More...

#include <GpuParticleBuffer.hpp>

Public Types
enum class	Mode { Storage , Vertex }

Public Member Functions
void	init (SDL_GPUDevice *dev, uint32_t maxBytes, Mode mode=Mode::Storage)
	Allocate GPU + transfer buffers of maxBytes each.
void	quit ()
	Release all GPU resources.
void	upload (SDL_GPUCommandBuffer *cmd, const void *data, uint32_t count, uint32_t stride)
	Upload count * stride bytes from data to the GPU buffer.
void	bindAsVertexStorage (SDL_GPURenderPass *pass, uint32_t slot) const
	Bind as a vertex storage buffer at the given slot.
void	bindAsVertex (SDL_GPURenderPass *pass) const
	Bind as a vertex buffer at binding index 0.
uint32_t	liveCount () const
uint32_t	capacityBytes () const

Private Attributes
SDL_GPUDevice *	device_ = nullptr
SDL_GPUBuffer *	gpuBuf_ = nullptr
SDL_GPUTransferBuffer *	transfer_ = nullptr
uint32_t	capacity_ = 0
	Bytes allocated.
uint32_t	liveCount_ = 0
	Updated by upload().

Detailed Description

Manages a GPU storage buffer + CPU-side transfer buffer pair for particle data.

Two usage modes are supported:

Storage mode (default): GPU buffer created with SDL_GPU_BUFFERUSAGE_GRAPHICS_STORAGE_READ. Vertex shaders read particle data as a readonly storage buffer via gl_InstanceIndex. Bound with bindAsVertexStorage().

Vertex mode: GPU buffer created with SDL_GPU_BUFFERUSAGE_VERTEX. Used for pre-expanded flat vertex streams (ribbon trails, lightning arcs). Bound with bindAsVertex().

In both cases upload() must be called inside a copy pass, BEFORE the render pass begins.

Member Enumeration Documentation

Mode

enum class GpuParticleBuffer::Mode

strong

Enumerator
Storage
Vertex

Member Function Documentation

bindAsVertex()

void GpuParticleBuffer::bindAsVertex

(

SDL_GPURenderPass *

pass

)

const

Bind as a vertex buffer at binding index 0.

Precondition

Mode::Vertex, called inside a render pass.

bindAsVertexStorage()

void GpuParticleBuffer::bindAsVertexStorage	(	SDL_GPURenderPass *	pass,
		uint32_t	slot ) const

Bind as a vertex storage buffer at the given slot.

Precondition

Mode::Storage, called inside a render pass.

capacityBytes()

uint32_t GpuParticleBuffer::capacityBytes ( ) const

inlinenodiscard

init()

void GpuParticleBuffer::init	(	SDL_GPUDevice *	dev,
		uint32_t	maxBytes,
		Mode	mode = Mode::Storage )

Allocate GPU + transfer buffers of maxBytes each.

liveCount()

uint32_t GpuParticleBuffer::liveCount ( ) const

inlinenodiscard

quit()

void GpuParticleBuffer::quit

(

)

Release all GPU resources.

upload()

void GpuParticleBuffer::upload	(	SDL_GPUCommandBuffer *	cmd,
		const void *	data,
		uint32_t	count,
		uint32_t	stride )

Upload count * stride bytes from data to the GPU buffer.

Opens and closes its own SDL_GPUCopyPass internally. Must be called BEFORE SDL_BeginGPURenderPass.

Member Data Documentation

capacity_

uint32_t GpuParticleBuffer::capacity_ = 0

private

Bytes allocated.

device_

SDL_GPUDevice* GpuParticleBuffer::device_ = nullptr

private

gpuBuf_

SDL_GPUBuffer* GpuParticleBuffer::gpuBuf_ = nullptr

private

liveCount_

uint32_t GpuParticleBuffer::liveCount_ = 0

private

Updated by upload().

transfer_

SDL_GPUTransferBuffer* GpuParticleBuffer::transfer_ = nullptr

private

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The documentation for this class was generated from the following files:

• src/client/particles/GpuParticleBuffer.hpp
• src/client/particles/GpuParticleBuffer.cpp